This is great news!

At the same time it's too little too late. I still won't forget how they killed the VST2 SDK and came after people who hosted copies. This was terrible for people who tried to build existing open source VST2 plugins. It was even worse for people who wanted to write a VST2 host, but couldn't get a license anymore. This was at a time when VST3 support was far from universal and many plugins didn't ship VST3 versions. (Not to mention all the existing plugins that never will.)

I mean, these "SDKs" are just goddamn header files! *) They shouldn't have been proprietory in the first place. Now, if they also re-release the VST2 SDK under the MIT license and apologize for their crass behavior, then I will actually give them credit.

/rant off

*) Yes, the VST3 SDK is huge, but the only things you really need are the headers in https://github.com/steinbergmedia/vst3_pluginterfaces/tree/m.... The VST2 SDK only consistet of two header files (aeffect.h and aeffectx.h)